CHAPTER 7
RNA Structure and Function
CONTENTS
7.1 RNA Structural Motifs 253
7.1.1 Basic Structural Features of RNA 254
7.1.2 Base Pairings in RNA 255
7.1.3 RNA Multiple Interactions 256
7.1.4 RNA Tertiary Structure 257
7.2 RNA Processing and Modification 263
7.2.1 Protecting and Targeting the Transcript: Capping and Polyadenylation 263
7.2.2 Splicing and Trimming the RNA 264
7.2.3 Editing the Sequence of RNA 269
7.2.4 Modified Nucleotides Increase the Diversity of RNA Functional Groups 271
7.2.5 RNA Removal and Decay 272
7.3 RNAs in the Protein Factory: Translation 273
7.3.1 Messenger RNA and the Genetic Code 273
7.3.2 Transfer RNA and Aminoacylation 275
7.3.3 Ribosomal RNAs and the Ribosome 276
7.4 RNAs Involved in Export and Transport 280
7.4.1 Transport of RNA 280
7.4.2 RNA that Transports Protein: the Signal Recognition Particle 280
7.5 RNAs and Epigenetic Phenomena 281
7.5.1 RNA Mobile Elements 281
7.5.2 SnoRNAs: Guides for Modification of Ribosomal RNA 282
7.5.3 Small RNAs Involved in Gene Silencing and Regulation 283
7.6 RNA Structure and Function in Viral Systems 283
7.6.1 RNA as an Engine Part: The Bacteriophage Packaging Motor 283
7.6.2 RNA as a Catalyst: Self-Cleaving Motifs from Viral RNA 285
7.6.3 RNA Tertiary Structure and Viral Function 287
References 2907.1 RNA Structural Motifs
RNA is the most versatile macromolecule in nature. The linear sequence of an RNA can encode large
amounts of complex information that is subsequently transformed into functional proteins. However, many